全文获取类型
收费全文 | 2739篇 |
免费 | 190篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 26篇 |
妇产科学 | 68篇 |
基础医学 | 394篇 |
口腔科学 | 45篇 |
临床医学 | 305篇 |
内科学 | 612篇 |
皮肤病学 | 35篇 |
神经病学 | 333篇 |
特种医学 | 131篇 |
外科学 | 369篇 |
综合类 | 7篇 |
一般理论 | 1篇 |
预防医学 | 68篇 |
眼科学 | 43篇 |
药学 | 238篇 |
中国医学 | 2篇 |
肿瘤学 | 228篇 |
出版年
2023年 | 20篇 |
2022年 | 20篇 |
2021年 | 117篇 |
2020年 | 66篇 |
2019年 | 79篇 |
2018年 | 80篇 |
2017年 | 56篇 |
2016年 | 88篇 |
2015年 | 95篇 |
2014年 | 117篇 |
2013年 | 136篇 |
2012年 | 203篇 |
2011年 | 229篇 |
2010年 | 133篇 |
2009年 | 103篇 |
2008年 | 186篇 |
2007年 | 221篇 |
2006年 | 170篇 |
2005年 | 186篇 |
2004年 | 160篇 |
2003年 | 147篇 |
2002年 | 144篇 |
2001年 | 24篇 |
2000年 | 20篇 |
1999年 | 20篇 |
1998年 | 16篇 |
1997年 | 11篇 |
1996年 | 7篇 |
1995年 | 12篇 |
1994年 | 10篇 |
1993年 | 2篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1970年 | 2篇 |
1969年 | 2篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有2937条查询结果,搜索用时 78 毫秒
1.
2.
3.
4.
5.
6.
Evgeny Sidorov Courtney Iser Nidhi Kapoor Bappaditya Ray Juliane Chainakul Chao Xu Andrei V. Alexandrov David Lee Gordon 《Journal of stroke and cerebrovascular diseases》2021,30(8):105890
ObjectivesIntravenous (IV) tissue plasminogen activator (tPA) should be given to patients with acute ischemic stroke (AIS) and avoided in stroke mimics (SM). Select use of emergency brain magnetic resonance imaging (eMRI-brain) in stroke-alerts aids diagnosis, but accepted utilization criteria for eMRI-brain do not currently exist. We developed criteria for eMRI-brain and report the yield of eMRI-brain in stroke-alert patients.Materials and MethodsWe developed three history-based criteria for performing eMRI-brain during stroke-alerts: (1) history of previous similar deficits, (2) change in consciousness at onset of symptoms, (3) symptom presentation consistent with migraine aura. We then performed a retrospective chart review of patients who presented as a stroke-alert over a 5-year period and determined how these criteria affected administration of IV tPA to AIS and SM patients.ResultsAmong 3,512 stroke-alerts, 230 (8.1%) patients met our criteria for eMRI-brain exams: 217 (92.6%) had SM and 17 (7.4%) had AIS. Our IV tPA decision-making analysis showed that based on eMRI-brain IV tPA was less frequently administered to SM patients (PCC-0.841, p=0.036) with less failures to administer IV tPA to patients with AIS (PCC -0.907, p-value=0.013, Pearson correlation coefficient). No patients became ineligible for IV tPA due to MRI-related time delays.ConclusionsOur history based criteria for performing eMRI-brain during stroke-alerts show a high yield of stroke mimics. Selective eMRI-brain improves decision-making accuracy regarding IV tPA administration. 相似文献
7.
8.
Andrei S. Morgan Jennifer Zeitlin Karin Klln Elizabeth S. Draper Karel Marl Mikael Norman Fredrik Serenius Stef van Buuren Samantha Johnson Valrie Benhammou Vronique Pierrat Monique Kaminski Laurence Foix L'Helias Pierre-Yves Ancel Neil Marlow 《Acta paediatrica (Oslo, Norway : 1992)》2022,111(1):59-75
9.
Agustín Estrada-Peña Sally Cutler Aleksandar Potkonjak Muriel Vassier-Tussaut Wim Van Bortel Hervé Zeller Natalia Fernández-Ruiz Andrei Daniel Mihalca 《International journal of health geographics》2018,17(1):41
Background
The bacteria of the group Borrelia burgdorferi s.l. are the etiological agents of Lyme borreliosis in humans, transmitted by bites of ticks. Improvement of control measures requires a solid framework of the environmental traits driving its prevalence in ticks.Methods
We updated a previous meta-analysis of the reported prevalence of Borrelia burgdorferi s.l. in questing nymphs of Ixodes ricinus with a literature search from January 2010–June 2017. This resulted in 195 new papers providing the prevalence of Bb for 926 geo-referenced records. Previously obtained data (878 records, years 2000–2010) were appended for modelling. The complete dataset contains data from 82,004 questing nymphs, resulting in 558 records of B. afzelii, 404 of B. burgdorferi s.s. (only 80 after the year 2010), 552 of B. garinii, 78 of B. lusitaniae, 61 of B. spielmanii, and 373 of B. valaisiana. We associated the records with explicit coordinates to environmental conditions and to a categorical definition of European landscapes (LANMAP2) looking for a precise definition of the environmental niche of the most reported species of the pathogen, using models based on different classification methods.Results
The most commonly reported species are B. afzelii, B. garinii and B. valaisiana largely overlapping across Europe. Prevalence in ticks is associated with portions of the environmental niche. Highest prevalence occurs in areas of 280°–290° (Kelvin) of mean annual temperature experiencing a small amplitude, steady spring slope, together with high mean values and a moderate spring rise of vegetation vigor. Low prevalence occurs in sites with low and a noteworthy annual amplitude of temperature and the Normalized Difference Vegetation Index (colder areas with abrupt annual changes of vegetation). Models based on support vector machines provided a correct classification rate of the habitat and prevalence of 89.5%. These results confirm the association of prevalence of the three most commonly reported species of B. burgdorferi s.l. in Europe to parts of the environmental niche and provide a statistically tractable framework for analyzing trends under scenarios of climate change.10.
Barasch A Gordon S Geist RY Geist JR 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2003,96(2):136-140
Necrotizing oral lesions have been described in immunosuppressed patients, usually in association with gingival and periodontal pathoses. The etiology of these lesions has not been completely elucidated. We present 3 patients with a type of necrotizing stomatitis in which clinical patterns appear distinct from the periodontal forms of the disease. The lesions yielded bacterial cultures positive for Pseudomonas aeruginosa and reverted to no growth in 2 patients after proper antibiotic therapy. We propose that P aeruginosa may be responsible for selected necrotizing oral lesions with a clinical presentation lacking typical necrotizing periodontal disease and that this condition may represent the intraoral counterpart of ecthyma gangrenosum. In such cases, bacterial culture of the lesion becomes imperative because the disease does not respond to typical periodontal and antimicrobial therapy. 相似文献